Experimental Investigation on the Effects of Swirlers Configurations and Air Inlet Partitioning in a Partially Premixed Double High Swirl Gas Turbine Model Combustor

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Amir Mardani ◽  
Benyamin Asadi Rekabdarkolaei ◽  
Hamed Rezapour Rastaaghi

Abstract In this work, a double-high swirl gas turbine model combustor (GTMC) has been experimentally investigated to identify the effects of air partitioning and swirlers geometry on combustion characteristics in terms of flame stability, exhaust gas temperature, NOx generation, and combustion efficiency. This high swirl model combustor is originally developed in the German Aerospace Center (DLR) and known as GTMC and recently reconstructed at Sharif University's Combustion Laboratory (named as SGTMC). Here, SGTMC run for liquefied petroleum gas (LPG) fuel and air oxidizer at room temperature and atmospheric pressure. Eleven different burner geometries, M1–M11, are considered for the aims of this work. Furthermore, the effects of burner confinement are also investigated. The results show that under the confined state, the flame has a lower width and height than the unconfined one. Exchanging the swirlers of annular and central air inlets shows a more stable and lifted V type flame with almost zero levels of CO and CH4. In addition, measurement showed that the annular swirler removing leads to incomplete combustion. Moreover, an increment in discharged air velocity leads to more completed combustion and less pollutant exhaust gas but the attachment of flame to the burner hub. Strengthening the flow channeling is not reasonable in terms of emission aspects. Moreover, burner configuring to counterrotating swirlers leads to a more stable flame but with lower combustion efficiency. Among 11 test cases, the original configuration and the case of exchanging the swirlers of annular and central air inlets are the best choices in terms of combustion efficiency and stability. Measurements show the improvement of burner stability, 2–10%, due to inlet air preheating.

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5950
Author(s):  
Jinfu Liu ◽  
Mingliang Bai ◽  
Zhenhua Long ◽  
Jiao Liu ◽  
Yujia Ma ◽  
...  

Failures of the gas turbine hot components often cause catastrophic consequences. Early fault detection can detect the sign of fault occurrence at an early stage, improve availability and prevent serious incidents of the plant. Monitoring the variation of exhaust gas temperature (EGT) is an effective early fault detection method. Thus, a new gas turbine hot components early fault detection method is developed in this paper. By introducing a priori knowledge and quantum particle swarm optimization (QPSO), the exhaust gas temperature profile continuous distribution model is established with finite EGT measuring data. The method eliminates influences of operating and ambient condition changes and especially the gas swirl effect. The experiment reveals the presented method has higher fault detection sensitivity.


Author(s):  
Anand Nageswaran Bharath ◽  
Nitya Kalva ◽  
Rolf D. Reitz ◽  
Christopher J. Rutland

Low Temperature Combustion (LTC) strategies such as Reactivity Controlled Compression Ignition (RCCI) can result in significant improvements of fuel economy and emissions reduction. However, they can produce significant carbon monoxide and unburnt hydrocarbon emissions at low load operating conditions due to poor combustion efficiencies at these operating points, which is a consequence of the low combustion temperatures that cause the oxidation rates of these species to slow down. The exhaust gas temperature is also not high enough at low loads for effective performance of turbocharger systems and diesel oxidation catalysts (DOC). The DOC is extremely sensitive to exhaust gas temperature changes and lights off only when a certain temperature is reached, depending on the catalyst specifications. Uncooled EGR can increase combustion temperatures, thereby improving combustion efficiency, but high EGR concentrations of 50% or more are required, thereby increasing pumping work and reducing volumetric efficiency. However, with early exhaust valve opening, the exhaust gas temperature can be much higher, allowing lower EGR flow rates, and enabling activation of the DOC for more effective oxidization of unburnt hydrocarbons and CO in the exhaust. In this paper, a multi-cylinder engine system simulation of RCCI at low load operation with early exhaust valve opening is presented, along with consideration of the exhaust aftertreatment system. The combustion process is modeled using the 3D CFD code, KIVA, and the heat release rates obtained from this combustion are used in a GT-Power model of a turbocharged, multi-cylinder light-duty RCCI engine for a full system simulation. The post-turbine exhaust gas is fed into GT-Power’s aftertreatment model of the engine’s DOC to determine the catalyst response. It is confirmed that opening the exhaust valve earlier increases the exhaust gas temperature, and hence lower EGR flow rates are needed to improve combustion efficiency. It was also found that exhaust temperatures of around 457 K are required to light off the catalyst and oxidize the unburnt hydrocarbons and CO effectively. Performance of the DOC was drastically improved and higher amounts of unburnt hydrocarbons were oxidized by increasing the exhaust gas temperature.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Zhi-tao Wang ◽  
Ning-bo Zhao ◽  
Wei-ying Wang ◽  
Rui Tang ◽  
Shu-ying Li

As an important gas path performance parameter of gas turbine, exhaust gas temperature (EGT) can represent the thermal health condition of gas turbine. In order to monitor and diagnose the EGT effectively, a fusion approach based on fuzzy C-means (FCM) clustering algorithm and support vector machine (SVM) classification model is proposed in this paper. Considering the distribution characteristics of gas turbine EGT, FCM clustering algorithm is used to realize clustering analysis and obtain the state pattern, on the basis of which the preclassification of EGT is completed. Then, SVM multiclassification model is designed to carry out the state pattern recognition and fault diagnosis. As an example, the historical monitoring data of EGT from an industrial gas turbine is analyzed and used to verify the performance of the fusion fault diagnosis approach presented in this paper. The results show that this approach can make full use of the unsupervised feature extraction ability of FCM clustering algorithm and the sample classification generalization properties of SVM multiclassification model, which offers an effective way to realize the online condition recognition and fault diagnosis of gas turbine EGT.


Author(s):  
Giancarlo Chiatti ◽  
Ornella Chiavola

A comparative series of experimental tests has been performed on a 4-stroke multi cylinder indirect injection diesel engine fueled with diesel oil, pure gas-turbine fuel and gas-turbine fuel with additives. The engine has been equipped aimed at monitoring both the overall performances and the variation with time of the pressure in the pre-combustion chamber. Some key parameters have been investigated at different engine speeds and loads (ignition delay, pressure rise in the pre-combustion chamber, power output, specific fuel consumption, exhaust gas temperature) and discussed results are presented.


2012 ◽  
Vol 586 ◽  
pp. 342-348
Author(s):  
Zhen Ning Zhao ◽  
Jing Jing Wang ◽  
Zhen Zhou Zhao ◽  
Qing Feng Zhang

The exhaust gas temperature correction for the change of air inlet temperature is the most significant correction for boiler performance test. However, in ASME and China GB standard, the regulations of the correction formulas are different, which brings about some misunderstanding in actual use. In this paper, the correction formulas are derived and analyzed. What’s more, the application conditions are summed up and described as follows. Firstly, the top and side of the air heater must be in good sealing ability, for which the air leakage can be ignored. Secondly, the air inlet temperature must be taken from the entrance of the air heater, but not from that of the forced draft fan. Finally, the air leakage of the air heater must stay the same before and after the correction. On this basis, a correction method is conducted, which takes the cold air temperature at the entrance of the forced draft fan as the air inlet temperature and can be applied under different air leakage ratios conditions. With the same form as the traditional one, the method mentioned above is easy to understand and has a positive meaning in handling such problems.


2019 ◽  
Vol 22 (1) ◽  
pp. 295-315 ◽  
Author(s):  
Reza Golzari ◽  
Hua Zhao ◽  
Jonathan Hall ◽  
Mike Bassett ◽  
John Williams ◽  
...  

Introduction of ever more stringent emission regulations on internal combustion engines beyond 2020 makes it necessary for original equipment manufacturers to find cost-effective solutions to improve the combustion engine efficiency and decrease its emissions. Highly efficient combustion engines can benefit from technologies such as cooled external exhaust gas recalculation and water injection. Among these technologies water injection can be used as a promising method to mitigate knock and significantly reduce the CO2 emissions. This is particularly important in highly downsized boosted engines which run under much higher intake pressures and are more prone to knocking combustion. In addition to anti-knock behaviour, water injection is also an effective method for reducing NOx emissions and exhaust gas temperature at high loads, which can protect the turbine in turbocharged engines. This study shows the influence of intake port injection of water on efficiency and emissions of a boosted downsized single-cylinder gasoline direct-injection engine in detail. Six different steady-state speed and load combinations were selected to represent the conditions that knocking combustion start to occur. Water ratio sweep tests were performed to find out the optimum water/fuel ratio at each test point and the impact on the combustion and emissions. In addition to gaseous emissions, impact of water injection on particle emissions was also investigated in this study. The results show the net indicated efficiency improved significantly (by a maximum of around 5% at medium load and around 15% at high load) up to a maximum level by increasing the injected water mass. Improvement in efficiency was mainly due to the increased heat capacity of charge and cooling effect of the injected water evaporation which reduced the in-cylinder temperature and pressure. Thus, knock sensitivity was reduced and more advanced spark timings could be used, which shifted the combustion phasing closer to the optimum point. However, increasing the water/fuel ratio further (more than 1 at medium load and more than 1.5 at high load) deteriorated the combustion efficiency, prolonged the flame development angle and combustion duration, and caused a reduction in the net integrated area of the P-V diagram. Efficiency improvements were lower at higher engine speed (3000 r/min) as the knock sensitivity was already reduced intrinsically. In terms of other, harmful, non-CO2 emissions, water injection was effective in reducing the NOx emissions significantly (by a maximum of around 60%) but increased the HC emissions as the water/fuel ratio increased. The results also show a significant reduction in particle emissions by adding water to the mixture and advancing the spark timing at medium and high loads. In addition, water injection also reduced the exhaust gas temperature by around 80°C and 180°C at medium and high loads, respectively.


Author(s):  
Branko Stankovic

A gas-turbine-cycle modification has been proposed, optimized primarily for (district) heating purposes, with a side-effect of obtaining gas-turbine exhaust gas at very low temperatures and potentially GHG-emission-free. Since its primary purpose is district heating without power generation, the associated gas-turbine-cycle equipment (compressors, turbines, heat exchangers) is typically arranged so that a maximum possible ratio of heat output and heat input is achieved. Whenever the heat ratio is greater than unity, that is, greater than 100% of the heat input, the exhaust gas temperature at the last gas-turbine exit is lower than atmospheric temperature. In other words, this means that it is possible to achieve greater heat output (or GT-cycle “waste heat”) than the heat input, at the “expense” of the cold GT exhaust gas (its internal energy). It is possible to arrange proposed GT-cycle modification in various configurations, such as: simple GT cycle, recuperated, intercooled, intercooled-recuperated, reheat-recuperated and intercooled-reheat-recuperated GT cycle. Maximum achievable ratio of heat output and heat input is estimated to about 1.15 (115%) and corresponding minimum GT exhaust gas temperature can be lower than the CO2 solidification temperature at atmospheric pressure (−78°C or 195 K or −108.4°F). This also means that the GT exhaust-gas stream could be entirely GHG-emission-free, without GHG-s like H2O and/or CO2, which could therefore be captured and sequestered in solid state, and in addition at very low refrigerating temperature. Such low-temperature GT exhaust gas could then be used for refrigeration purposes, or ultimately to refrigerate the Earth’s atmosphere and thus mitigate global-warming effects. The proposed GT-cycle heating system can operate also in the combined heating/cooling and power (CCHP) mode or in the stand-alone power generation mode using a combined-cycle configuration. In such operating modes/regimes, the heating part of the CHP system could still maintain its inherent advantages (achievement of the ratio of heat output and heat input greater than unity, potentially GHG-emission-free GT exhaust gas at refrigerating temperature levels), with CC thermal efficiencies only slightly lower than today’s typical values and with the CHP performance similar or better than modern GTCC or steam-turbine based CHP cycles.


Author(s):  
V. N. Guruprakash ◽  
Ranjan Ganguli

Measured health signals incorporate significant details about any malfunction in a gas turbine. The attenuation of noise and removal of outliers from these health signals while preserving important features is an important problem in gas turbine diagnostics. The measured health signals are a time series of sensor measurements such as the low rotor speed, high rotor speed, fuel flow, and exhaust gas temperature in a gas turbine. In this article, a comparative study is done by varying the window length of acausal and unsymmetrical weighted recursive median filters and numerical results for error minimization are obtained. It is found that optimal filters exist, which can be used for engines where data are available slowly (three-point filter) and rapidly (seven-point filter). These smoothing filters are proposed as preprocessors of measurement delta signals before subjecting them to fault detection and isolation algorithms.


2011 ◽  
Vol 18 (3) ◽  
pp. 37-42 ◽  
Author(s):  
Zbigniew Korczewski

Exhaust gas temperature measurements in diagnostic examination of naval gas turbine engines: Part II Unsteady processes The second part of the article presents the results of operating diagnostic tests of a two- and three-shaft engine with a separate power turbine during the start-up and acceleration of the rotor units. Attention was paid to key importance of the correctness of operation of the automatic engine load control system, the input for which, among other signals, is the rate of increase of the exhaust gas flow temperature. The article presents sample damages of the engine flow section which resulted from disturbed functioning of this system. The unsteady operation of the compressor during engine acceleration was the source of excessive increase of the exhaust gas temperature behind the combustion chamber and partial burning of the turbine blade tips.


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